<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style>
    *{
      margin:0;
      padding: 0;
      list-style: none;
    }
    .Ui_box li:nth-child(1){
      margin-left:0px;
    }
    .UI_box li:hover{
      color:orange;
    }
    .Li_box{
      width:100px;
      height:200px;
      background-color: aqua;
      border-top:1px solid black;
      position:relative;
      top:100px;
      left:0px;
    }
   .Ul_box{
     width:800px;
     height:100px;
     border:1px soild green;
     margin: 0 auto;
   }
   .ul_box li{
     float:left;
     font-size:20px;
     margin-left:20px;
     line-height:100px;
   }
    </style>
</head>
<body>
  <div class="box"> 
    <ul class="Ul_box">
         <li>小米手机</li>
          <li>Redmi手机</li>
          <li>电视</li>
          <li>笔记本</li>
          <li>平板</li>
          <li>家电</li>
          <li>路由器</li>
          <li>服务中心</li>
         <li>社区</li>
    </ul>
  </div>
</body>
</html>